<!DOCTYPE html>
<html>
<body>

<p>Click the button to display a confirm box.</p>

<button onclick="myFunction()">Try it</button>

<p id="demo"></p>

<script>
function myFunction()
{
var x;
var r=confirm("Press a button!");
if (r==true)
  {
  x="You pressed OK!";
  }
else
  {
  x="You pressed Cancel!";
  }
document.getElementById("demo").innerHTML=x;
}
</script>

</body>
</html>